A hybrid electric vehicle or an electric vehicle has the advantages of economy, energy saving and environmental protection, etc., and has become the main focus of research and development for the major automobile companies under the crisis of energy shortage. With the advance of the automobile industry, vehicle amount has been increasing, and the pressure from the environmental pollution and the energy shortage has become obvious. At present, as the world is running out of fossil fuel, and the situation of global warming is getting urgent, countries around the world regard energy saving and environmental protection as the prior direction of development for the future automobile industry. With their obvious features of high efficiency, energy saving, low noise and null emission, electric vehicles have an incomparable superiority in the aspect of energy saving and environmental protection. In recent years, the electric vehicles have achieved great improvements in the core technologies such as power battery, electrical motor, control system, and on board charger module. The safety, reliability, and lifetime of products are significantly raised, and the manufacturing cost is under a certain level of control. Hybrid electric vehicles and electric vehicles are gradually entering the stage of practical use and small industrialization, and will be the strategic direction of the development of the automobile industry.
As one of the key components of electric vehicle, a charger module can be classified as an off board charger module and an on board charger module (OBCM). The off board charger module, which is also referred to as a ground charging device or a charging pile, often has a larger power, larger volume, and greater mass. The OBCM is a device mounted on an electric vehicle for charging a battery pack by the AC power grid, in which an AC power cable is plugged into a socket of the electric vehicle to get it charged. The OBCM is essentially a power conversion device. The OBCM uses input wires to receive alternative current which is coupled to AC power grid, and outputs high voltage direct current to charge the on board high voltage battery pack, and uses a communication port to maintain real-time interactive communications with a battery management system (BMS). The overall performance enhancement and the cost control of the OBCM are always key factors restricting the mass production of electric vehicles, and the structure design and the thermal management of the OBCM are ones of the most critical indicators for comprehensively evaluating the performance of the OBCM.
However, the OBCM, or the power conversion device, consumes a lot of electricity, the electronic components in the power conversion device generate quite a lot of heat with the increasing of power density of the OBCM or device, and if the electronic components do not physically contact the heat spreaders, the heat-dissipating efficiency is limited and the heat transferring performance is not good.
In view of the foregoing, there still exist inconvenience and defects in the aforementioned conventional hardware configuration, and further improvements need to be made. In order to solve the above problems, those who are in related fields have made a lot of efforts, but suitable solutions have not been developed. Therefore, how to enhance the heat-dissipating efficiency is becoming an important R&D topic, and is a goal that urgently needs to be improved.